I have a client who would like to shoot color film/video and increase
the black level optically. The goal is to drop in a "Hi-Con" filter (maybe in various grades) to increase contrast neutrally (darken
shadows) while maintaining all other levels and ideally with a very
small amount of T-stop compensation.

Of course a hi-contrast color image can be created 'in-camera' with
lighting, and some contrast can be gained outdoors with a Polarizer.
However this goal of the 'hi-con filter' would be different, more akin
to a yellow, orange or red filter in B&W photography.

While I like the concept, I don't think that this sort of filter is
possible- at least for color film. Video does have that capability in
the menu. You mention all the possible ways that contrast actually can
be increased with the exception of the haze filter. The "skip bleach"
process will increase contrast, and there are filters that will "enhance"
certain colors.

Years ago I assisted a DP who insisted that an ND (neutral density)
filter would increase contrast. I don't think so. There are subtle things
happening there that you could say would actually reduce contrast…hardly
noticeable though.

I personally dislike any filter that reduces contrast- low cons and
"milky" diffusion filters. However, having said that I almost
always use a rear net for video which does reduce contrast. I would
tell your client the best place to control contrast is in post. Only
there can you fine tune and get exactly what you see.

Edwin Myers, Atlanta dp

Illya Friedman wrote:

>I have a client who would
like...to drop in a "Hi-Con" filter

Filters that lower contrast abound. They do the relatively simple job
of redirecting light available in the scene in a manner that effectively
lightens shadows with minimal effect on highlights. They don't have
to distinguish between highlight areas and shadow areas; its just that
when the filter adds, say, 1% of the overall luminance to the entire
scene, it has a greater effect on shadows than highlights, (because
while you won't notice the addition of 1% to 99%, adding 1% to 0% is
very noticeable) thus reducing the apparent difference between them
and thus "lowering contrast."

Filters that alter grey scale tonality in black-and-white imaging work
because while they are intense enough to bias one part of the spectrum
at the expense of another, their color is removed as an issue because
the recording medium is color-blind and only sees shade of grey. This
doesn't really apply well to color imaging.

The filters that under certain circumstances can be said to increase
contrast optically like polarisers, color enhancers, and haze filters,
work only in very specific situations that may not apply to what you
are trying to do.

To truly create a "Hi-Con" filter, it would have to increase
the difference between highlight and shadow luminance levels. It could
lighten highlights and/or darken shadows. To do so, it would have to
be able to intelligently differentiate between highlight and shadow
areas, unlike in the low contrast example, because what you do to one
has to be the opposite of what you do to the other. To increase contrast,
you can't simply add or remove light from everything equally, and this
is what makes it harder to do.

As far as I am aware, a filter that does this won't available in time
for your current project, so electronic manipulation in post is probably
your best bet.

Ira Tiffen
The Tiffen Company
Hauppauge, NY 11788

Regarding a potential Hi-Con filter, Brian Heller wrote :

>Any idea of when it might
be ready?"

Unfortunately, I am not in a position to divulge such proprietary information
at this time.
Ira Tiffen
The Tiffen Company
Hauppauge, NY 11788

Ira Tiffen wrote :

>Unfortunately, I am not in
a position to divulge such proprietary >information at this
time.

Still working on how to shift those annoying Laws of Physics?

Ira's just having a little fun but for those that don't realize it,
anything that is placed in front of a lens will cause some degree of
scattering of light, therefore reducing contrast. This is infinitesimally
true even for an optical flat. Due to certain properties under specific
conditions, a few filters such as Polarisers, haze filters and Enhancing
filters can effectively increase the relative contrast of an image.
But in general there is no such thing nor will there ever be such a
thing as an optical Hi-Con filter.

Mitch Gross
NYC DP

Ira Tiffen Writes:

>Unfortunately, I am not in
a position to divulge such proprietary >information at this
time.

Mitch Gross writes in reply :

>Still working on how to shift
those annoying Laws of Physics?

I have the highest regard for Ira's abilities and I'm willing to wait.
Of course, I'd like to see an adjustable version; you know, the kind
with the little knob on the side.

Brian Heller
IA 600 DP

Mitch Gross wrote:

>anything that is placed in
front of a lens will cause some degree of >scattering of
light, therefore reducing contrast.

As Ira pointed out, lowering contrast is simply a matter of adding exposure
across the entire frame to effectively fog the shadow areas of the picture
whilst leaving the highlights relatively unaffected. The conceptual
Hi-Con filter would need to intelligently distinguish areas of shadow
or light in the frame and either suppress exposure (for shadow areas)
or augment it (for highlights) to increase the apparent contrast of
the image.

This is of course impossible - in front of the lens. However if the
filter is positioned behind the lens, sufficiently close to the film
plane, then it could 'react' selectively to the areas of shadow and
light in the resolved image passing through it.

Then all one would need to do would be to find some phlogiston to add
the glass and hey presto! A Hi-Con filter.

I'm thinking of marketing them in fact and if anyone try’s to
sue me I'll just tell them that the name derives from, Highly Improbable-Confidence
trick.

Tom Townend,
Cinematographer/London.

Has anyone done more testing with the Tiffen Soft Con filter?

This filter is suppose to reduce contrast by adding density to the highlight
areas ... rather then the typical adding light to the shadow areas.

By making the highlights darker...it can create an illusion of more
contrast...by making everything a bit darker. Of course if one lightened
everything back to "normal"...the effect was one of slight
diffusion. Supposedly (Ira?) one isn't suppose to compensate for this
filter, that definitely has an ND quality to it...varying in density
by grade of filter.

The only extended project that I know of that used Soft Cons through
out... was "Blue Sky," Dp'ed by Steve Yaconelli. I AC'ed on
that film for a few days. We did however compensate for the filter's
density...and so the effect was minimized.

I played around using Soft Cons on my home Hi-8 camera years ago...and
it could darked highlights...and it did seem to increase apparent contrast.

Perhaps the fellow that was asking about a Hi-Con filter could experiment
with Soft-Cons ...

Mako, Makofoto Images, Glendale, CA

>This filter is suppose to
reduce contrast by adding density to the >highlight areas...rather
then the typical adding light to the shadow areas.

Couldn't you also use ND grads or attenuator grads to selectively darken
bright areas in the frame and increase apparent contrast?

They would increase the apparent contrast of areas which would otherwise
be over-exposed w/out the ND grad.

For example, instead of the sky being blown out and white, it would
be blue and white clouds would be visible there by increasing the amount
of detail in the frame and the apparent contrast of the image.

>By making the highlights darker
... it can create an illusion of more >contrast ... by making
everything a bit darker."

In reply, Jessica wrote :

>Couldn't you also use ND grads
or attenuator grads to selectively >darken bright areas
in the frame and increase apparent contrast?"

Soft Contrast filters are a combination of our standard Low Contrast
filter series with an ND 0.3 in each grade. That means there is a consistent
one-stop light reduction throughout the Soft-Con range, and only the
light scattering component which lowers contrast increases in strength
with increasing grade number.

The concept centres around wanting to
render highlights darker than they would otherwise appear, to show more
highlight detail, and to specifically do so in a manner that fits in
with the often-used practice of maintaining a particular T-stop to better
maintain lens sharpness and depth-of-field characteristics. Used the
way we suggest, not compensating for exposure, the filter will darken
highlights by one stop, which, if it were just an ND filter, in darkening
everything by one stop you would not see a real change in contrast.

The difference is that the low contrast component will still lighten
shadows. The net result is that you have raised shadow luminance AND
reduced highlight luminance simultaneously. You could accomplish this
by closing down a stop and using a Low Contrast filter, but you would
have to make the stop adjustment, which may be undesirable. When you compensate for the one stop of the Soft Con filter, you are
effectively taking advantage of it as an ND filter to allow for a larger
lens opening while retaining its ability to lighten shadows and reduce
contrast.

Think of exposure adjustments as able to either raise or lower luminance
levels of everything. Highlights up, shadows up; highlights down, shadows
down. The only time this results in an apparent increase in contrast
is in parts of the scene that are either black from underexposure or
white from overexposure; in either instance, adjusting exposure will
bring out more detail and thus more apparent contrast. But contrast
is still the difference between the luminance levels of highlights and
shadows, and to effectively increase this you may need to be able to
treat both differently, as I have written earlier.

Grads and attenuators will allow overly bright areas to come closer
to being properly exposed at the same exposure that you would use for
getting good detail in otherwise darker areas, such as with an overly
bright sky- a ND 0.6 grad will usually be enough to allow good detail
in the average bright sky as well as in the darker foreground. However,
these filters will not have an increasing or decreasing effect on actual
contrast apart from the particular circumstances of apparent contrast
changes I refer to above.